Abstract - Clarification of sweet cheese whey by thermocalcic aggregation of residual fatClarification of sweet cheese whey was studied by using the property of lipoproteins to aggregate under heat treatment when ionic calcium is added. Optimization of process parameters was obtained through systematical study of amount of calcium to be added to the whey, pH adjustment and heating temperature, holding time being fixed at 20 s. A clarified whey with an optical density at 600 nm similar to the one of milk ultrafiltrate and with a nitrogenous matter content representing 85 % of those existing in the original whey was obtained when 8. g.L-1 of calcium as CaCl2 was added, when pH was adjusted to 6.0 and when heating temperature was 78-79° C.The proposed whey treatment leads to an aggregation and a reduction of hydrophily of lipoproteic complexes which are quickly decanting at low temperature. Supernatant and sediment analysis showed that around 80 % of original β-lactoglobulin and 85 % of initial α-lactalbumine remain soluble in clarified whey.Clarified whey can be used either for preparing crystal clear soft drinks with or without addition of flavours, or as a pastry base with a high foaming capacity. For example, a pasteurized mix for meringue making can be prepared. On the other hand, uses of the sediment will be large and diversified not only in traditional dairy products but also in dietetic foods because of its high content in phospholipids